The present invention relates to a method of controlling the ignition timing of an internal combustion engine.
A well-known ignition timing control system of an internal combustion engine controls the ignition timing by detecting engine parameters that represent the operating conditions of an internal combustion engine, e.g., detecting the rotational speed of the engine, flow rate of the intake air, pneumatic pressure in the intake manifold, to calculate the ignition timing, and instructing the ignition at a calculated timing. In the system of this type, under some conditions the ignition timing is often fixed to a predetermined constant value, since engine parameters such as rotational speed, undergo great variation when the engine is being started or until a predetermined period of time has passed after starting.
However, when the rotational speed of the engine is greatly raised while the ignition timing has been fixed to a predetermined value as mentioned above, the period for storing energy in the ignition coil becomes too short causing misfire to occur, or the period during which the flow of current to the ignition coil is interrupted becomes short so that the ignition coil overheats, and a power transistor for controlling the primary current to the ignition coil is often destroyed by the heat.